Dual pump unit to supply different hydraulic pressures for engine and transmission



May 15, 1962 FRENCH, JR 3,034,288

DUAL PUMP UNIT TO SUPPLY DIFFERENT HYDRAULIC PRESSURES FOR ENGINE AND TRANSMISSION Original Filed June 14, 1954 3 Sheets-Sheet 1 ENGINE WITH THROTTLE THROTTLE. RCTUHTEP Tkrmsmsslou 3 IE. 17 Ta T Alfred G. fiendh Jr:

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May 15, 1962 A. G. FRENCH, JR DUAL PUMP UNIT TO SUPPLY DIFFERENT HYDRAULIC PRESSURES FOR ENGINE AND TRANSMISSION Original Filed June 14, 1954 3 Sheets-Sheet 2 Alfred G. fiezzcfz (/1? i fl z z 1 75 y 1962 A. e. FRENCH, JR 3,034,288

DUAL PUMP UNIT TO SUPPLY DIFFERENT HYDRAULIC PRESSURES FOR ENGINE AND TRANSMISSION Original Filed June 14, 1954 3 Sheets-Sheet 3 Alfred G, Wench (fr:

United States Original application June 14, 1954, Ser. No. 436,557, now

Patent No. 2,962,969, dated Dec. 6, 1960. Divided and this application Mar. 30, 1959, Ser. No. 807,970

. 9 Claims. (CI. 60-12) The present invention relates to improvements in means for simultaneous fixed and variable displacement of fluid such asmay be especially useful in connection with apparatus utilizing oil under pressure for different through corelated or cooperative, or at least conjointly operative purposes.

This application is a division of my copending application Serial No. 436,557, filed June 14, 1954, now Patent No. 2,962,969, issued December 6, 1960.

In automotive vehicles employing fluid drive transmissions, both the source of motive power, that is, the engine, and the transmission require hydraulic fluid in constant supply under pressure. It has heretofore been customary to provide a plurality of separate or at least individual hydraulic pressure systems for creating the desired hydraulic pressure, and more particularly for engine lubrication and for transmission operation. This has been so even under conditions and operating requirements enabling use of the same oil for both engine lubrication and hydraulic transmission operation/ The prior arrangement has therefore entailed complexities of design, multiplication of pumping units and therefore of the motivating means or drive shafts required therefor, with the attendant high equipment costs, uneconomic operation, maintenance difficulties, and the like.

An important object of the present invention is to provide a central fluid motivating and pressure system motivated by a single power source or mechanism and. functioning in a novel manner not only to displace hydraulic fluid under fixed displacement between coordinated, co-

operative, or contemporaneously operating fluid utilizing units, but also to supply such units with individual variable pressure fluid requirements in operation.

Another object of the present invention is to provide a variable displacement pump system for simultaneously providing from a common fluid source fluid supplies under different pressures to difierent operating units.

A further object of the invention is to simplify and consolidate or centralize the hydraulic system for both engine lubrication and transmission operation in automotive vehicles.

Other objects, features and advantages of the present invention will be apparent. from the following detailed description of an exemplary embodiment of the invention taken in conjunction with the accompanying drawings, in

"atent FIGURE 1, and taken generally on the line II- II of FIGURE 3;

FIGURE 3 is a sectional elevational view taken substantially on the line III III of FIGURE 2;

FIGUREA is a sectional elevational view takensubstantially on line IV-"-IV-of FIGUREZ;

FIGURE 5 is a sectional elevat-ional view taken sub stantially on the line VV of FIGURE 2;

FIGURE 6 is a sectional elevational view taken substantially on the line VI-VI of FIGURE 2;

FIGURE 7 is a fragmentary sectional view taken substantially on the line VIIVII of FIGURE 6;

FIGURE 8 is a fragmentary sectional elevational view taken substantially on the line VIIIVIII of FIGURE 6; and

FIGURE 9 is a fragmentary sectional elevational view taken substantially on the'line IX-IX of FIGURE 6.

As shown schematically in FIGURE 1 a single pump unit id is operable to accommodate hydraulic fluid displacement and pressure conditions or requirements in both an engine having a throttle (as indicated by its legend in FIGURE 1) and a transmission (as indicated by its legend in FIGURE 1) which may, for example, comprise cooperable and functionally integrated components of an automotive vehicle such as an automobile wherein the engine drives the transmission for propelling the vehicle. In addition, the engine in suitable manner drives the pump unit it] which for this purpose is provided with a driven shaft 11 which has an end arranged to be drivingly coupled to a driving shaft 12 (FIG. 2) such, for example, as the distributor shaft of the internal combustion engine which may rotate atone-half engine speed. For this purpose, the pump unit 10 is preferably mounted on the underside of the engine block, herein identified at 13.

Herein, the pump unit It!" comprises two simultaneously operable pump means or sections operated by the shaft 11 and comprising a variable displacement constant pressure pump section or member 14- and a fixed or positive displacement pump member or section 15. The variable displacement constant pressure pump member 14 operates to draw oil from a supply source such as a sump 17 of the engine on the lower part of the engine block 13 through the medium of a suction conduit or duct 18 leading from the sump 17 to the pump section 14. The oil derived is driven under pressure by the pump section 14 into a delivery passage or duct 19 from which one branch 20 leads to the engine and another branch 21. leads'to the transmission.

Since different oil pressures are required for engine lubrication and converter charge, and for transmission replenishment and charge, means are provided for auto matically controlling pump delivery for these different purposes. provided in the pressure fluid branch duct 20} leading to the engine which will automatically assure proper operating pressure, in a typical instance ranging from about 20 pounds per square inch at engine idling speed to a. maximum operating or running speed pressure for the- To this end, a reducing valve structure 22 is square inch to-SO pounds per square inch, a regulating valvestructure 23 is provided which, in the present in stance, directly controls both the pressure and volume or displacement output of the pump 14, inasmuch as the a primary purpose of the pump section 14 is to supply the transmission fluid requirements. V a In an efiicient arrangement, the displacement and pressur'e controlling or regulating valve 23 is constructed and 'of the valve 23 to dynamic pressure fluid from the pump, j ;a connection is provided to negative or low pressure as gflby 'm e'ans of a duct or connection 25 leading from the yalye to the low pressure side of. the pump section 14 as, for example, the suction passage 18. Respective pumpcontrolling pressure shunt'ducts -277and 28 lead from the regulating valve, structure 23 to'the pumpsection 14.

Thereby, responses of the valve structure 23 to variations in pump pressure will berefiec'tedfthrough the shunt ducts 27 and 28 in regulatory variations in pump displacement,

.for example, to maintain a given fluid displacement or volume supply such as, in a typical instance, approximately one and one-half gallons per. minute to the transmission at all speeds of operation of the associated vehicle.

For controlling pump discharge in proportion to vari able service requirements under certain conditions, the

regulating valve 23 maybe controlled, as for example, in

a given-relationship to throttle opening of the internal combustion engine with whichitis" associated. For this purpose a control valve 29 is connected by a duct 30 to the high pressure conduit 19, 21 and to the valve assembly 23 by a pressure duct 31 and may be appropriately disposed to be operated through the medium of an operator such as a lever 32 arranged to be motivated by a connecting link or the like 33,1eading from the throttle mechanism of the as- 1 sociated vehicle asshown by the legend for this part 33 in FIGURE 1. In a typical instance, it may be determined that the pump discharge pressure should be between 50 and 90 pounds per square inch from idling speed to high speed of the vehicle motivating system including the engine and the transmissiori.;

-In service the pump section 15 serves as a scavenge pump operating as a fixed'or positive displacement fluid.

motivating means for pumping an air-oil mixture from a transmission sump 34 by'way of a suction duct or con- .duit 35 leading operatively to the pump unit, from which the oil' is then discharged through a conduit or duct 37 into the engine sump 17 where it becomes part of the main oil supply source. The oil in the transmission sump 34 is derived, of course, from transmission leakage or dumping incidental to its operation.

In an cflicient, economical, compact construction, the pump unit 10 comprises a'prim'ary housing 38 for the variable displacement, constant pressure pump 14, a secondary housing member 39 for the fixed displacement .pump '15, and a separator or divider plate member 40, in assembly allgsecured solidly together as by means of screws or bolts 41. Dowels 42 (FIGS. 3, 4 and may also be utilizedfor maintaining the housing components ,in proper assembly alignment.

.10 'to the engine block 13 may be eflected by means of screws 43'and 44 (FIGS. 2 3 and 6).

Attachment of the unit In addition to the preferred three-part construction of I preferably flat face (FIGS. 2

and 3) within which is a substantial cavity or recess 47 for operativelyhousing the variable'displacement, constant pressure pump as sembly 14. At its opposite end the housing block 38 has a second preferably flat face 48 (FIGS. 2 and 6) which, for the particular purpose and in view of a typical practical application, is disposed at an oblique angle relative to the face 45 and sloping from the top of the unit away from theface 45, whereby a substantial mass of the housing block 38 is provided between the inner wall defining the puurnp cavity 47 and the face 48, and more particularly between the cavity and the lower portionof the oblique face. It is the face 48 that is adapted to be secured to the engine block 13, and a sealing gasket 48a is preferably-interposed between the opposed abutting en-gineblock and housing block faces. 7

Inalpreferred form, the pump 14 is of. the rotary,

' sliding vane type. To thisend'the pump 14 comprises a circular rotor 49 concentrically mounted upon and corotat-ably keyed by means of a key 50 to an intermediate portion of the shaft 11 which projects concentrically through the pump cavity 47 and is rotatably supported by a bearing 51 within a bore 52 extending through the portion of the housing body 38 between the cavity 47 and the oblique face 48 for registration with a. shaft clearance opening 53 through the engine block wall sothat the pump shaft can be coupled corotatably with the, driving shaft 12. In diameter the rotor 49 is substantially smaller than the diameter of the pump cavity or recess 47 so that a'reciprocable modulator ring 54 can be accommodated in spaced relation about the rotor within the pump cavity; A uniformly spaced series of radially'reciprocable vanes 55 slidably mounted in respective radial slots 57 in the rotor are maintained by floating backing rings 58, accommodated in respective larger diameter recesses 59 in the opposite ends of the rotor 49, in engagement at the outer ends with the circular wall defining a pump chamber 60 within the modulator 54.

For variable displacement reciprocal adjustment of the modulator 54, it is provided with parallel opposite flat longitudinal sides6-1 slidably cooperable with parallel elongated flat bearing wall portions 62 defining opposite sides of thecavity 47. Longitudinally, the'cavity 47 is longer than the length of the modulator 54. Thereby, the modulator divides the modulator chamber provided by the cavity 47 into opposite, herein lower-and upper sub-chambers63 and 64, respectively. By preference, and in the interest of conservingspace, the opposing surfaces defining the-opposite ends of the modulator 54 and thew alls defining the sub-chambers 63 and 64 are of complementary arcuate shape.

Normally the modulator 54 is biased toward one end of the modulator chamber 47, herein toward the upper end, by means such as a' coiled compression spring 65 thrusting at one end against the central portion of the wall defining the sub-chamber 63- audat its opposite end against the modulator within a socket 67 provided therefor. By preference the biasing thrust of the spring 65 is fairly light so that it actually comprises merely a priming bias to assure normal eccentric relation of the pump chamber 60 relative-to the rotor 49, thereby conditioning the pump 14 for maximum displacement. In this displacement condition of the purnp, the upper endofthe modulator 54, as'shown in FIG. 3, extends into the sub-chamber 64 to the maximum extent permitted by a limit stop boss 68 which thrusts against the wall defining the sub-chamber64 and assures at all times at. least a minimum spaced relation between the a modulator and the wall of the sub-chamber 64;

.When the shaft i1'1 .is driven clockwise as viewed in FIG. 3, and the rotor 49-is thereby rot-atcdin the-same direction,.action of the rotor bladesor vanes 55 within the pump chamber 60 causes hydraulic fluid to :be sucked from theen-gine sump 17 through the intake .passage 18 I 47 and located on the low pressure or suction side of the pump to feed into the gradually increasing volume space between the rotor and the pump chamber in the maximum eccentric relation of the modulator to the rotor. As the hydraulic fluid is carried toward the opposite diminishing volume side of the pump chamber by the pump vanes 55, the fluid is placed under pressure and is forced into the discharge passage 19' which comprises in its principal part an arcuate, kidney shaped port recessed into the inner wall defining the modulator chamber 47, in counterpart to the low pressure port 70 but disposed on the high pressure side of the pump for reception of the pressure fluid as impelled by the pump.

From the high pressure passage port 19, the high pressure fluid passes in major volume through the passage or duct 21 in part extending through the lower portion of the housing member 38 and thence through suitable conduit means serving as an extension of the housing por tion of the passage 21, to the transmission. A smaller volume of the pressure fluid passes from the high pressure passage port 19 into the engine lubrication passage which also extends through and is provided as primarily a bore in the lower portion of the housing member 33 with a blind end directed through the face 48 of the housing member 38 and normally closed off in assembly by the gasket 48a (FIGS. 2 and 6).

Herein, the valve structure 22 is mounted in the lower portion of the housing member 38 in controlling relation to the pressure passage 21 (FIGS. 2, 6 and 8). To this end the valve structure 22 comprises a reciprocable plunger valve member 71 longitudinally slidably reciprocably mounted in a bore 72 provided in the housing member 38 in intersecting relation to the passage bore 20 and opening from one side of the housing. A closure plug 73 for the outer end of the bore 72 serves as a fixed abutment for a biasing spring 74 preferably of the coiled compression type thrusting inwardly against the adjacent end portion of the valve plunger 71 about a reduced diameter stem portion 75 normally opposing the fixed plug 73 in spaced relation and serving to limit reciprocal movement of the valve plunger 71 toward the plug 73 in opposition to the spring 7 4.

Pressure fluid from the passage port 20 acts upon a shoulder 77 on the plunger valve 71 to move the valve plunger 71 in opposition to the bias of the spring 74 after predetermined pressure for which the spring 74 has been selected, has been attained. Such pressure movement of the valve 71 will cause cracking of a passage from the valve chamber 72 into a lubricating oil delivery passage 78 in the housing body 33 and leading through the face 48 to a duct 79 provided in the engine block 13 and in suitable manner communicating with the lubricating system for the engine. a

A pressure relief vent opening 89 extends from the spring housing portion of the valve chamber 72 through the face 48 and communicates with a relief vent port 81 opening into the lubricating oil chamber within the engine block 13. Detrimental pressure build-up about the reducing valve 71 is avoided or relieved by a relief passage 82 leading from the valve chamber 72 from intermediate the output passage 78 and the relief passage 89 to a relief groove 83 recessed in the face 43 of the housing block 38 and communicating with the pump shaft bore 52 which in turn communicates through the engine block opening 53 with atmosphere. Additional pressure relief for the valve is provided through a port 84 communicating with a reduced diameter portion 85 at the inner end of the valve chamber and within which a slidable reduced diameter head 86 of the valve body 71 is reciprocable. The pressure relief vent port 84 opens through the face 48 of the housing and communicates 'with' a relief recess 87 cored in the opposing face of the engine block 13 and communicatively overlapping a groove 88 in the face 48 leading to the shaft bore 52.

For variable displacement control of the modulator 54,

the regulator valve structure 23 preferably comprises a .sure passage port 19 and the low pressure port 70 at the respectively opposite end portions of the valve chamber bore. The end portion of the valve chamber bore 90 which opens into the high pressure port 19 is of reduced diameter and provides the communication passage 24 through which high pressure fluid is operable againstthe head portion of the valve 89 to drive the valve way from an abutment limit shoulder 91 'in opposition to a biasing spring 92 loaded for apredeterminedprcssure such as '50 pounds per square inch thrusting at one end against the base end of the valve plunger 89 and at its opposite end against a thick abutment 93 which is preferably in the form of a closure member threaded into the outer end portion of the valve chamber bore 90.

In the spring biased limit position of the valve 89 against the shoulder 91 pressure fluid communication by way of a blind end bore 94 through outlet ports 95 and an external valve groove 97 escapes into the passage 28 comprising a bore opening through the face 48 of the housing block 38 and communicating with a generally J-shaped groove 98 in the face 48 leading to a port or passage 99 (FIGS. 3, 6, 7 and 9) by which pressure fluid is delivered in operation to the modulator sub-chamber 63 for maintaining the modulator 54 in the initial phases of operation and until predetermined pressure has been developed in its maximum eccentric position.

When the pump pressure exerted on the valve member 89 attains the predetermined or mean pressure for which the spring 92 has been selected, the valve member is moved in opposition to the spring and by compression of the spring to close 01f the pressure port or passage 28 by overlapping thereof by a solid or land area of the valve member intermediate the peripheral annular groove '97 and an annular peripheral somewhat wider groove 100 in the valve member which is in continual communication with a low pressure bleed port'or passage 191 which opens through the housing face 48 intov the pressure relief groove 83. I I 7 When pump pressure exceeds the predetermined mean, sensitivity of the valve 89 to the excess pressure causes it to move further in opposition to the spring 92 until communication is effected between the shunt duct 28 and the peripheral valve groove 100 andpressure thereby from the modulator sub-cham-' relieved or exhausted ber 66.

Coincidental with such pressure relief from the mod lator sub-chamber 63, pressure fluid is introduced to the opposite modulator suhchamber 64 for thereby shifting the modulator toward reduced eccentricity, and thereby reduced displacement and pressure, until the mean pressure has been reestablished. Pressurizing of the sub: chamber 64 is accomplished as a result of the over-pressure movement of the valve 89 until pressure communication is effected by way of the pressure shunt duct or passage 27 which comprises a port through the housingface 48 to a groove 102 recessed 'therein'and leading to I a port 10% opening into the sub-chamber 64 (FIGS. 3'

. 111 of the pump guesses .tion of the valve chamber -bore 90 into which the low pressure or suction post of the pumpopens, hence 7 providing low pressure to'that modulator sub-chamber 94-97 and passages 128 -98-99, thus efiecting a pressure differential on the opposite ends of the modulator 54 assuring stability against torque forces tendingto shift tive to the pump rotor.

8 closed by the separator or divider plate 40 which on its opposite side closes the pump chamber 47. A hollow boss 118 provides a bore which in part atleast accommodates the suction passage leading to the low pressure or inlet side of the pump 15. At the high pressure or discharge side of the pump 15 the discharge or.deliv-- lery passage or duct 37 is accommodated by a hollow boss 119 preferably leading downwardly and opening Upon overtravel of valve body 89 to effect reversal of the pressure differential wherein the pressure shunt duct 2 8 is opened to atmosphere'as described, and the shunt the valve, automatic adjustment" of the modulator 54 occurs substantially instantaneously; and at the mean pressure the valve shifts to neutral or modulator locking position wherein both of the shunt duct ports 27 and 28 are closed off by the valve.

Over-riding of the valve 89 under sudden pressure surges is prevented by a stop member 104 having a stop end normally spaced at predetermined distance from the base end of the valve member 89.; Herein the stop stem 104 is substantially smaller diameter and disposed concentrically within the coiled biasing spring 92 and comprises an extension from a plunger head 105 reciprocably' slidably disposed within an inwardly opening counterbore 107 in the plosure member 93. Normally thestop member head 105 seats against a shoulder 108 at the internal end of the counterbore 107. When it is desired to increase the operating or mean pressure of the'pump 114' pressure fluid is introduced by way of the passage 31 which enters the closure member 93 concentrically with the counterbore 107 behind the stop member head 105.

In the initial phases of operation of the pump 14 the passage 31 may be neutralized or even vented for negative pressure by operation of the-valve 29, for example.

ample, normally the springbias upon the valve -89 may b approximately 50 pounds per square inch, whereas I when the pressure fluid bias isadded through the memher 104, pressuresup to 9.0P0unds per square inch may become the mean, thus accommodating yariablelrequirements in operation of the vehicle with which the system s asso i ted duct 2.7 communicatesrwithr the pressure groove 97 of During variable displacement, constant selected pressure operation of the pump 14', the pump 15 operates o -Witl1 fixed displacement to scavenge hydraulic fluid from the transmission sump 34 and return the same to the motor sump 17. Complete separation between the circulatory systems of the pumps 14 and 15 is eifected by the separation plate 40 of the. pump unit 10. In addi tion, the plate 40 serves as a journal support for the pump drivingshaft ll'which projects therethrough in a bearing 109 (FIG. 2) with the outer end portion of the shaft secured as by means of akey-110corotatably into a rotor Herein the pump 15 is of the sliding'vane type and for this-purpose the rotonlllis equipped with radial equally spacedtransverse slots 112 within which fluid displacing vanes 113 are slidably radially rcciprocably accommodatcd and operatively controlled :by inner and outer concentrio backing rings '114 engaging the inner endsof the varies and accommodated in respective recesses 115 in the opposite axial faces of the rotor 111 (FIGS. 2 and 4).

A circular wall eccentrically disposed pump chamber 117 is' provided 'asja. recess within the outer housing member 39 vof the .pumpfunit. This chamber opens to-i ward the inner face of thehousing, member :39 .an'dis into a registering complementary aperture 120 in the divider plate 40 and a complementary discharge passage 121 provided in a hollow outlet boss portion 122 in the lower portion of the main housing member 38 from which suitable conduit means continuing the passage 37 leads to the motor sump 1'7.

In order to assist in thefluid displacement function of the pump rotor 111 and the vanes 113, thevface portion of the divider plate 40 exposed to the pump chamber 117 is preferably provided with arcuate generally kidneyshaped low pressure and high pressure fluid grooves 123 and 124 (FIG. 5) of gradually varying depth at respectively the low and high pressure sides of the pump.

In order to avoid leakage from between the joints at the interfaces between the divider plate 40 and respectively the housing members 33 and 39, suitable pressure seals are provided. To this end, an annular groove 125 encircles in slightly spaced relation the area on the outer face ofthe divider plate 40 which provides the inner wall for the pump chamber 117; Within this groove is seated a resilient sealing ring such as an O-ring placed under compressive pressure by the opposing face of the housing member 39 clamped thereagainst. Similarly, a sealing groove 123 encircles in spaced relation the port 120 at the outer face of the divider plate and a resilient sealing O-ring 129 is seated therein and placed under compression by the housing member 39. At the interface of the divider plate 40 clamped against the'housing member 38, a sealing ring 130 is set into a suitable .annular groove surrounding the. pump chamber 47 in spaced relation, and a sealing ring 131 is set intoan annular groove in spaced relation about the port 120. These sealing rings 130 and 131 are placed under compression against the housing face 45. j a I From the foregoing it will be apparent that the single multi-function pump unit 10 serves to maintain a continuous cyclical pressure fiuid operational system performing highly efiiciently'in a self-propelled motor ve.-

hicle organization with which associated. Not only are substantial manufacturing and assembly economies'effected in the pump and control assembly but also compact space limitations are accommodated and operating efiiciency attained, since both pumps in the unit are driven from a single shaft by a single power source.

It Will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

i claim as my invention:

1. A fluid displacement assembly providing individual pressure'and volume requirements of hydraulic fluid for lubrication of an engine having a sump and providing transmission replenishment and recirculation of spenthydraulic fluid; a single unitary, compact housing having therein'a pair of rotary pumps on a common drive shaft arranged to be driven 'by'such an engine, the first of said pumps being of the fixed, positive displacement type and the second of said pumps being of the variable, posioperative to control the variable displacement of said second and variable displacement pump.

2. A fluid displacement assembly for lubricating an automotive engine having a sump, for replenishment of a transmission associated with such an engine and for scavenging from such transmission for return to such a sump comprising a two pump unit on a common drive shaft having fluid circulation connections, the first one of said pumps having connections for scavenging spent fluid from such a transmission and for returning such fluid to such an engine sump, the first of said pumps being of said unit of the fixed, positive displacement type and the second of said pumps being of the variable, positive displacement type, a supply connection conducting fluid from such an engine sump to the second of said 'pumps, pressure fluid connections from said second Of said pumps conducting fluid to the lubrication supply of such an engine and to such a transmission for replenishment, first valve means positioned in said pressure fluid connections for reducing the pump pressure in the connection to such an engine, and second valve means positioned in said pressure fluid connections automatically operative in the connection to such a transmission for controlling the displacement of said second pump and controlling the higher pressure supply to such a transmission.

3. A fluid displacement assembly for' continuous, cyclical use for the lubrication of an automotive vehicle engine having a sump and for the replenishment of a fluid transmission and scavenging of fluid from said transmission for return to said sump of such an engine comprising a unitary housing having therein and thereon a two pump unit on a common drive shaft connected to be driven by said engine and having fluid circulation connections, the first of said pumps being of the fixed, positive displacement type connected to scavenge fluid from the transmission for return to the sump of such an engine and the second of said pumps being of the variable, positive displacement type, a supply connection conducting fluid from such an engine sump to the second of said pumps, pressure fluid connections from the second of said pumps conducting fluid to such an engines lubrication supply and to such a transmission for replenishment, first valve means in said housing and positioned in said pressure fluid connwtions for reducing the pump pressure in the connection to such an engine and second valve means in said housing and positioned in said pressure fluid connections automatically operative in the connection of such a transmission for controlling the displacement of said second pump and for controlling the pressure at which said second pump supplies fluid to such a transmission.

4. An engine having a lubrication system, a fluid displacement structure including a pump housing having a recess with a pump therein and a high pressure pump discharge passage therefrom, said housing having a branch passage from said discharge passage leading to such a lubricating system of such an engine, a valve bore in one axial end of said housing intersecting said branch passage, a plunger valve operative in said bore, means normally biasing said plunger valve in one direction in which it blocks communication from said bore to such an engine lubricating system, said plunger valve being operative in response to fluid pressure to move in the op posite direction for controlling movement of pressure fluid through said branch passage tosuch an engine lubrication system and valve means in said one axial end of said housing for relieving said plunger valve from excessive pressure build-up.

5. A system for supplying oil under pressure to the lubrication system of an engie having an oil sump with an attachment face and to an oil pressure actuated transmission connected to such an engine for driving a load; a unitary pump housing having an attachment =face secured to such an attachment face of such an oil sump, said pump housing having passages therein operatively connected to said pump and connected to the lubrication system of such an engine, certain of said passages opening through said pump housing attachment face, said pump housing also having passages operatively connected to supply oil under pressure to such a transmission, a positive displacement pump in said housing and operatively connected to said passages, a pressure reduction valve in said housing at its attachment face connected to control the pressure of oil from said pump and supplied to such an engine lubrication system through said passages, and a second pressure control valve in said hous-' ing at its attachment face and operatively connected to supply oil from said pump to such a transmission at a higher pressure.

6. For use in a vehicle including a driving engine with a lubrication oil system, a throttle, and an oil pressure ctuated transmission operatively connected to such an engine for driving a load; an oil pressure supplying and displacement system comprising a variable, positive displacement pump driven by such an engine, said pump having first valve means having a connection supplying a lower pressure from said pump to such an engine lubrication system, second means including a valve having a connection supplying a higher pressure from said pump to actuate such a transmission and also connected to control the displacement of said pump responsive to its output pressure, and a third valve means actuated by. such an engine throttle and operatively connected to Said pump and to second means to modify the setting of said second means. i

7. For use in a vehicle including a driving engine with a lubrication oil system, an engine sump, a throttle and an oil pressure actuated transmission operatively connected to such an engine for driving a load; an oil pressure supplying and displacement system comprising a variable, positive displacement pump driven by such an engine, said pump being enclosed in a unitary housing adjacent to, and connected to, such an engine sump, said system including first valve means having a connection supplying a low pressure [from said pump to such an engine lubricating system, second means including a valve having a connection to supply a higher pressure from said pump to actuate such a transmission and also connected to control the displacement of said pump responsive to its output pressure, and a third valve means connected to, and operated by, such an engine throttle, said third valve means being operatively connected to said pump and to said second means to modify'the setting of said second means, at least said first two means being located in said pump housing between said pump and such an engine sump.

8. In combination with an engine having a lubrication oil system, an engine sump, and a throttle, an oil pressure actuated transmission operatively connected to said engine for driving a load, and an oil pressure supplying and displacement system comprising a unitary pump housing connected to said engine sump and having therein a variable, positive displacement pump adjacent to said sump and an outer and coaxial fixed, positive displacement pump, both pumps being driven by said engine, first valve means connected to supply a lower pressure fr'om'said variable displacement pump to said engine lubrication system, second valve means connected to supply a higher pressure from said variable displacement pump to actuate said transmission and including means connected to be re sponsive to the output pressure of said variable displacement pump for controlling its capacity and the setting of said second valve means, third valve means connected to said pump and to said second valve means and to be actuated by said throttle to vary the setting of said second valve means, and means providing connecting passages whereby said fixed displacement pump returns oil from said transmission to said engine sump and said variable displacement pump supplies oil from said, engine sump.

'9. In combination with an oil pressure actuated engine transmission and an engine having a lubrication oil system and an engine sump with an attachment face thereon, a unitary pump housing having an attachment face sefrom said sump to said pump and from said pump to said engine lubrication system and to said transmission, and means-to supply different pressures from said pump to said engine lubrication system and to said transmission and responsive to pump output pressure for controlling 10 the variable displacement of said pump, said means ineluding a plurality of valves located in said housing between said pump and its attachment face, at least one of i 2 said valves being an axially reciprocable and spring biased pressure reduction valve to reduce the pump pressure supplied to said engine lubrication system. 1

References Cited in the file of this patent 'UNITED STATES PATENTS 1,914,090 Hamilla et 'al June 13, 1933 2,186,748 Berger Jan. 9, 1940 2,608,880 Flinn n Sept. 2, 1952 2,651,179 Blood Sept. 8, 1953 2,761,276 Kollmann Sept. 4, 1956 2,833,374 Glasser May 6, 1958 

